Hello,
It's a DIKU MUD. At one time it was very lously
based on Silly MUD but we nearly rewrote 
everything so it's now it's own type in itself :)
(So it's a NexusMUD 2.6)

Address is : nexus.cohprog.com   port : 4000
But it's 4 or 5 years that nobody managed it
and I don't think that there is any players
left. (Well, some old players just asked me
if they could manage it so maybe....)
Probably several MUDs around there are using
our version as we distributed it...

Cheers,
Aldur
(err, I mean Yann Stettler)